Arctic winter sea ice has resumed a statistically significant long-term decline after two consecutive winters of exceptionally low ice cover, overturning earlier indications that losses had slowed in the early 2020s, according to a new study.


According to The Conversation, researchers said the record-low winter sea ice extent in 2025, followed by another near-record low in 2026, erased the apparent pause in the downward trend and reinforced evidence that Arctic warming continues to drive long-term ice loss.


The study found that the nearly 6% drop in winter sea ice extent between 2024 and 2025 was the largest single-year decline recorded since satellite observations began.


"Including these latest observations changes the picture of a weakened decline. Once the 2025 and 2026 winters are included, the 20-year trend in Arctic winter sea ice extent returns to a statistically significant decline. We can now be much more confident that the trend is real, and the decline is still ongoing," the researchers said.


Arctic sea ice is widely regarded as a key indicator of climate change. While the region has been warming much faster than the global average, satellite records since the late 1970s show sea ice has declined throughout the year, with the most pronounced losses occurring at the end of summer.


Scientists had noted that the rapid pace of winter sea ice decline appeared to ease during the early 2020s, prompting questions over whether the long-term trend had weakened. However, the latest findings suggest that slowdown was temporary rather than a lasting shift.


The researchers examined climate model simulations representing Arctic conditions warmed by about 3 degrees Celsius since 1980 and found that a one-year winter sea ice decline comparable to that seen in 2025 occurs only rarely, roughly once every 100 simulated years.


"This suggests that the 2025 drop was unusual, but still physically plausible. It does not require a new explanation. Instead, it is consistent with a warming Arctic in which year-to-year variability can produce abrupt changes," the study said.


Researchers cautioned that Arctic sea ice will continue to fluctuate from year to year, meaning not every winter will necessarily set a new record low.


"If warming continues, the same model simulations suggest that winter sea ice is unlikely to rebound to the higher levels seen in the early 2020s," they said.


The study added that while winter and summer sea ice are closely linked, a renewed decline in winter ice has not yet been matched by a similarly clear acceleration in summer sea ice loss. Researchers said weather patterns, cloud cover, ocean heat, snow cover and ice thickness would all influence how much ice survives through the summer melt season.


"The lesson, at least for winter, is that Arctic sea ice loss has not stopped. The apparent slowdown of the early 2020s looked real at the time, but now looks more like a pause than a lasting change. Short-term variability can temporarily mask decline, but it does not remove the underlying pressure from Arctic warming," the researchers said.


By Aghakazim Guliyev